Tag Archives: Java

Rotting Oranges

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In this tutorial, i am going to discuss a very interesting problem rotting oranges (minimum time required to rot all fresh oranges).

Given an m*n grid where each cell in the matrix can have values 0, 1 or 2.

0 represents an empty cell
1 represents cells have fresh oranges
2 represents cells have rotten oranges

Every minute, any fresh orange that is 4-directionally adjacent to a rotten orange becomes rotten.

Return the minimum number of minutes that must elapse until no cell has a fresh orange. If this is impossible, return -1.

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Valid Palindrome II | Delete at Most One Character to Make it a Palindrome

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In this tutorial, I am going to discuss a variation of palindrome questions valid palindrome II. In this problem, we can remove a character from a string to make it a palindrome.

Given a non-empty string, We may delete at most one character from a string. We have to write a code which checks whether we can make this string palindrome or not.

For example –

Example 1:

Input : “aba”
Output: true

This string is already palindrome. So we return true.

Example 2:

Input : “abca”
Output: true

This string is not a palindrome. But, if we delete either a character b or c from this string then the new string is a palindrome.

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Find Majority Element in an Array

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Given an array of size n, Write a code to find majority element in an array.

What is Majority Element?

The majority element is the element that appears more than n/2 times where n is the size of an array.

NOTE: For this problem you can assume that the array is non-empty and the majority element always exist in the array.

Example 1:

Input : [3, 2, 3]

Output: 3

The size of the array is 3 and the element which occurs more than 1 is the majority element. So three is the output.

Example 2:

Input: [2, 2, 1, 1, 1, 2, 2]

Output: 2

The element 2 occurs more than 3 times. So, It is the majority element.

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